Idempotency Handling Ensure operations produce identical results regardless of execution count. Idempotency Key Pattern Database-Backed Idempotency When to Apply - Payment processing - Order creation - Webhook handling - Email sending - Any operation where duplicates cause issues Best Practices - Require idempotency keys for mutations - Validate request body matches stored request - Set appropriate TTL (24 hours typical) - Use atomic database operations - Implement cleanup jobs to prevent table bloat TTL Cleanup Strategy To prevent unbounded table growth, implement periodic cleanup of expired…